Fillet welds are checked according to S16-14 - Chapter 13. The strength of CJP groove welds is assumed the same as the base metal and is not checked.

#### Fillet welds

The resistance for direct shear and tension or compression induced shear is designed according to S16-14 – 13.13.2.2. Plastic redistribution in weld material is applied in Finite Element Modelling.

\[ V_r = 0.67 \phi_w A_w X_u (1+0.5 \sin^{1.5} \theta ) M_w \]

where:

*ϕ*_{w}= 0.67 – resistance factor for weld metal, editable in Code setup*A*_{w}– area of effective weld throat*X*_{u}– ultimate strength as rated by the electrode classification number*θ*– angle of axis of weld segment with respect to the line of action of applied force (e.g., 0° for a longitudinal weld and 90° for a transverse weld)- \( M_w = \frac{0.85+\theta_1 / 600}{0.85+\theta_2 / 600} \) – strength reduction factor for multi-orientation fillet welds; equals to 1.0 in IDEA and the resistance of multi-orientation welds is determined by FEA where the most stressed element is assessed
*θ*_{1}– orientation of the weld segment under consideration*θ*_{2}– orientation of the weld segment in the joint that is nearest to 90°

Base metal capacity at the fusion face:

\[ V_r = 0.67 \phi_w A_m F_u \]

where:

*A*_{m}=*z L*– area of the fusion face*z*– leg size of the weld*L*– length of the weld*F*_{u}– specified tensile strength

The weld diagrams show stress according to the following formulas:

If base metal is deactivated (matching electrode is used):

\[ \sigma = \frac{\sqrt{ \sigma_{\perp}^2 + \tau_{\perp}^2 + \tau_{\parallel}^2 }}{1+0.5 \sin^{1.5}{\theta}} \]

If base metal is activated (matching electrode is not used):

\[ \sigma = \max \left \{ \frac{\sqrt{ \sigma_{\perp}^2 + \tau_{\perp}^2 + \tau_{\parallel}^2 }}{1+0.5 \sin^{1.5}{\theta}}, \, \frac{\sqrt{ \sigma_{\perp}^2 + \tau_{\perp}^2 + \tau_{\parallel}^2 }}{\sqrt{2} F_u / X_u} \right \} \]

#### CJP groove welds

The resistance of Complete Joint Penetration (CJP) groove welds is assumed as that of the base metal.